2018B Question 06

Outline the adverse effects which could occur following the rapid transfusion of ten units of packed red cells.

Examiner Report

80% of candidates achieved a pass in this question.

This question asks about a topic that is core to anaesthetic practice. Better answers included recognition that the rapid administration of ten units of blood constitutes a massive transfusion and were followed by a list of adverse effects with brief explanations of the cause and consequence of each effect. Adverse effects include storage lesion effects, immunological effects, coagulation sequelae, contamination risks and volume related problems. Also, better answers were well organized which reflected the necessary efficiency required to convey the maximal breadth and depth of the topic in 10 minutes. Parts of answers that did not attract any points included rephrasing the question and giving information that did not answer the question, such as detailed explanations of the blood collection process.

Model Answer


  • Introduction
  • Storage lesion
  • Overload
  • Dilution
  • Metabolic
  • Immune
  • Infective


Term Detail
Red Cell Unit Contents

- Red cells

- Small volume plasma

- Preservative: Sodium, adenine, glucose, mannitol

Massive Transfusion

- 50% blood volume in 4 hours, or 100% of BV in 24 hours

- 10 units = 2.5L = 50% blood volume

Ideal ratio of RBC:FFP:platelet

- 1:1:1

- May be situation-dependent

Lethal Triad

- Acidosis

- Hypothermia

- Coagulopathy

Storage Lesion

Factor Detail
Definition Adverse effects associated with storage of blood, that increase with the duration of red cell storage.

- Red cells: Spheroidal, rigid, fragile; 25% loss at 4/52
(free Hb 1 → 30μg/mL)

- White Cells: Inactivate but still antigenic

- Platelets: Inactivated at 48 hours?

Coagulation Factors

- Minimal since plasma removed

- FV 50% at 3/52

- FVIII 30% at 3/52


- Temp 4°C

- pH 7.4 → 6.7 (due to additives)

- K+ 4→30mM

- Ca2+ 2mmol.L-1 → ? (due to 3mg citrate)

- ATP 75%

- [2,3-DPG]: 50% at 2/52, 5% at 4/52 (due to low temp)

- ↑ Free haemoglobin


Of: Detail

- ↑ Blood volume → ↑ Preload

- May cause heart failure

- High risk if LV impairment


- Haemolysis → Hb breakdown → ↑ Free haemoglobin

- Risk of haemochromatosis → Damage to liver, pancreas, heart, pituitary


- Microvascular occlusion → Multi-organ dysfunction (especially lung)


Of: Detail
Coagulation Factors

- Dilutional coagulopathy

 - Coagulation factors esp fibrinogen

 - Platelets


- Hyperviscosity

 - ↑ Risk thromboembolism

 - ↑ Resistance to flow, ↑ myocardial work


Factor Detail
↓ Temperature

- Arrest if rapid via CVC

- Coagulopathy

↓ pH

- Arrest if rapid via CVC

- Negative inotropy

- Generalized metabolic dysfunction

↑ K+

- Arrhythmia, arrest if rapid via CVC

- Most K+ taken up by RBC upon transfusion

↓ Ca2+

- Arrhythmia, muscle weakness

- (Note hypocalcaemia severe enough to cause coagulopathy would already have caused cardiac arrest)

↓ 2,3-DPG - Left shift oxy-haemoglobin dissociation curve → ↓ Tissue oxygenation


Reaction Detail
Febrile non-haemolytic - Donor WBC → Cytokine release, fever
Febrile haemolytic

- i.e. Result if incompatible blood transfusion

- Donor RBC Ag + host RBC Ab → Haemolysis

 - ABO intravascular

 - RhD extravascular (reticuloendothelial system)

Anaphylaxis - Especially IgA deficient host
TRALI - Donor Ab + host WBC → Non-cardiogenic APO within hours
Cancer recurrence

- Increased risk

- Mechanism unknown


Disease Detail
Bacteria Septicaemia in 3% (certain pseudomonas species can multiply in the cold)
Viruses HBV, HCV, HIV; CMV
Parasites Malaria

Last updated 2021-08-23

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